Within the immediate area of a terrorist event, you would need to rely on police, fire, and other officials for instructions. However, you can prepare in much the same way you would prepare for other crisis events.
Citizen Corps, Homeland Security's grassroots effort, localizes preparedness messages and provides opportunities for citizens to get emergency response training, participate in community exercises and volunteer to support local first responders.
Move or leave if you feel uncomfortable or if something does not seem right.
Take precautions when traveling. Be aware of conspicuous or unusual behavior. Do not accept packages from strangers. Do not leave luggage unattended. You should promptly report unusual behavior, suspicious or unattended packages, and strange devices to the police or security personnel.
Learn where emergency exits are located in buildings you frequent. Plan how to get out in the event of an emergency.
Be prepared to do without services you normally depend on—electricity, telephone, natural gas, gasoline pumps, cash registers, ATMs, and Internet transactions.